Copying machine



March 1931- A. H. GLEDHILL 1,795,718

COPYING MACHINE Filed May 15, 1928 Jaw INVENTOR! Patented Mar. 10, 1931 ARTHUR HENRYGLEDHILL, or HALIFAX, ENGLAND COPYING MACH IKE Application filed May 15, 1928, Serial No. 278,017, and. in Great Britain May a, 1927.

This invention relates to machines for producing copies 0T drawings, documents and the like and to that type of machine in which the paper on which the copy is to be made is placed in a travelling feed carriage which lays the paper on to a duplicating composition. T his carriage is provided with a platen roller mounted in a pivoted frame and adapted to be lifted out of contact with a tension roller on the carriage to allow a sheet of paper to be fed into the carriage until it comes to Test against a stationary stop on the machine. Vvhen the platen roller is lowered it engages the sheet of paper against the tenleii sio'n roller and the continued movement of the frame to its lowered position, revolves the rollers and feeds the paper through with the result that a loop of paper is formed in 7 front of the platen roller by the time that the 3B latter arrives at its bottom or operative position. When the carriage is traversed to lay the sheet of paper on 'to the duplicating compositiomthe loop so formed produces creasing o the paper and causes it to be laid more or lesscro'okedly on'the composition, thereby u'p setting the alignment of the matter on the paper. Another cause of creasing the pa ier. laying it more or less 'crookedly on the platen, and obtaining unequally printed copies, is

.3 3 the diflic'ulty of usting the platen roller in relation to the plate'i'i and maintaining such adjustment when made. This adjustment is commonly elllect'ed by means of a set screw on "the carriage whichcan be adjusted in rela- 135 tion to an abutment on a slide to \Vl'lltl'l that end of the carriage is hinged. A very small turn "o f this set screw raises or lowers that end of the carriage quite perceptibly and it is difficult to get theexact adjustment. The adjustment when made is rigid and will not allow the roller to automatically adjust itself to various platens, or thicknesses of duplieating compositions, or to an unequal thickness in one duplicating composition and the adjustment when made is not permanent as in course of time the end of the adjusting screw forms an indentation in the abutmentwith the result that the adjustment is lost.

According to this invention means are provided whereby the platen roller can be returned to its operative position without forming any loop or'slack paper between the point where it acts upon the tension roller and the point at which it presses the paper against the composition.

This can be efi'ected by causing the tension roller to be held out of engagement with the platen roller until the latter almost arrives at its operative position whereupon the tension roller automatically 'returns to its operative position in relation to the platen roller.

To facilitate the adjustment of the platen roller in relation to the platen and to maintain such adjustmeilt when made a predetermined amount of lost mot-ion is provided in the hinge between the carnage and the slide and the platen-roller on the carria e is adjusted in relation to the platen, or c jupl'icating' composition by ineansof a yielding or sp'ring'adjustment which will allow the platen roller on the carriage to automatically adjust itself to inequalities in the thickncs ot the duplicating c('nn1 ():-;itions and mai in a practically uniform pressure between the platen roller and the composition over the whole surface of its travel.

In order that the said inveiition may he clearly understood ana -sanity carried into ellect, the same is described more fully with reference 'to the accompanying drawings, in 8 which 1 r Fig. 1 is a side elevation of part of a copying machin'e iitted with iii'iprovei'nei'it-s in accordance with this invention.

Fig. 2 is a view taken in the direction of the arrow indicated in Fig. 1.

Fig. 3 is a section of part of the carriage mechanism.

Fig. 4 is a detached view of part of the mechanism shown in Fig. 3.

Fig. 5 is a section taken through part of the carriage mechanism showing the tension roller and platen roller out of contact with one another, and

Fig. 6 is a section taken througli part of r the carriage showing an intermediate supporting roller for the platen roller.

A indicates the platen roller, B the tension roller, in e'rmediate suppemng'roner, and D the yielding or spring adjustment.

In the example shown the cranked ends a of the pivoted bracket or frame a which carries the platen roller A are formed with notches or recesses a and the arms I) which carry the tension roller B are formed with projecting surfaces 72 the arrangement being such that as the bracket or frame a is turned to lower the platen roller A on to the composition its cranked ends a first engage the projections b on the tension roller arms and move the tension roller B away from the platen roller A as shown in Fig. 5. Just before the roller A arrives at its bottom or operative position the notches or recesses a come into line with the aforesaid projections 6 and allow the tension roller B to assume its operative position in relation to the platen roller as shown in Figs. 3 and at.

A feature of the invention which is more particularly applicable to wide machines where the platen roller is liable to spring consists in mounting upon the platen roller carrier one or more supporting rollers C, Fig. 6, adapted to bea against one or more intermediate portions of the platen roller A and provided if desired with screw adjustment 0 whereby they can be regulated to prevent distortion of the platen roller and cause the latter to exert a uniform pressure over the whole width of the paper.

The yielding or spring adjustment to facilitate the adjustment of the platen roller in relation to the platen is shown made in the form of spring pressed plungers D carried by the carriage E and arranged to travel along paths f on the side frames F of the machine. The pressure that the plungers D exert upon such paths can be regulated by screws (Z which are provided with knurled heads or other turning (lOVlCCS to compress springs (Z to a greater or less extent and thereby regulate the pressure of the roller upon the composition. If desired the old grub screw adjusting device G may be retained for quickly giving a rough adjustment and the spring plungers D actuated to give the final. and resilient adjustment.

By the invention described a yielding or elastic adjustment is obtained and when the adjustment has been made it is to all intents and purposes permanent, as there is practically no wear between the plungers D and the paths 7 along which they travel. The adjustment can be more easily and accurately made as a complete turn of an adjusting screw d may make a very small dilference in the action of the spring d upon the plunger, the screw (Z being retained in its adjusted position by screwing the lock nut (Z against the carriage E.

What I claim as my invention and desire to secure by Letters Patent in the United States is 1. In a copying machine, a travelling feed carriage, a platen roller, a pivoted carrier for said roller mounted on the carriage, a tension roller on the carriage, and cooperable cam portions associated with said carrier and tension roller for moving the tension roller out of engagement with the platen roller when the platen roller is moved past the tension roller away from the operative position of the platen roller.

2. In a copying machine, a travelling feed carriage, a platen roller mounted in the carriage for movement to and from operative position, a tension roller mounted yieldingly on the carriage to bear against the platen roller, and portions between said rollers adapted to contact and move the tension roller away from the platen roller when the platen roller is moved away from operative position.

3. In a copying machine, a travelling feed carriage, a carrier pivoted on the carriage, a platen roller mounted in the carrier, arms pivoted on the carriage, a tension roller mounted in said arms, and spring means for swinging said arms to move the tension roller against the platen roller, said arms and carrier having cooperable cam portions for moving the tension roller away from the platen roller when the platen roller is moved from operative position.

4:. A copying machine comprising a frame, a traveling feed carriage, members for sup porting said carriage movably on the frame, sprin means between said members and carriage for yieldingly supporting the carriage from said members, and a platen roller mounted in said carriage.

5. A copying machine comprising a platen frame, a travelling feed carriage, plungel's slidably mounted in said carriage and slidable on the frame, springs between said plungcrs and carriage for yieldingly supporting the carriage, and a platen roller mounted in the carriage.

6. A copying machine comprising a platen frame having paths, a travelling feed carriage, plungers slidably mounted in said carriage and movable along said paths, adjust ing screws mounted in the carriage, springs confined between said plnngers and screws to yicldingly support the carriage from said plungers, and a platen roller mounted in said ca rriage.

In testimony whereof I hereunto aiiix mv signature. I

ARTHUR HENRY GLEDHILL. 

